IIAR 9 System Applicability

Our team has spent a lot of time working with our clients to help them navigate the applicability of best practices. In the field of ammonia refrigeration, the International Institute of All-Natural Refrigeration (IIAR) is known as our leading best practice, or what our industry refers to as "Recognized and Generally Accepted Good Engineering Practices" (RAGAGEP). This doesn't mean IIAR is the only option out there for ammonia refrigeration systems, but it is considered to be the most recognized by the industry.

The comprehensive IIAR Library, consisting of books 1-9, is the road map for a safe ammonia refrigeration system. The current IIAR Library includes the following books:

• Definitions (Book 1),

• Design (Book 2),

• Valves (Book 3),

• Installation (Book 4),

• Startup (Book 5),

• Inspection, Testing, & Maintenance (Book 6),

• Development of Operating Procedures (Book 7),

• Decommissioning (Book 8),

• Minimum Safety Requirements for Existing Ammonia Refrigeration Systems (Book 9)

All of the previously listed books in the IIAR Library work together for reaching compliance with IIAR standards. The book we're focused on during this blog is IIAR 9-2020 and its applicability to ammonia refrigeration systems. Many claim that it applies to all existing systems that are in operation but that is not necessarily the case and we'll explain why. IIAR book 9 was updated in 2024 to include a new flow chart to help clarify its applicability to existing systems (Addendum A-2024). The image below is a screenshot of the IIAR 9 flow chart:

IIAR 9 Flow Chart

Let's examine the initial point that asks, "Do you know the original codes/standards that governed?" So far, there is no indication that all ammonia refrigeration systems must adhere to IIAR 9 provisions. Here's a scenario where IIAR 9 would be applicable:

If you start working at a new facility and discover that their process safety information (PSI) for the ammonia system is virtually nonexistent (a common occurrence we deal with), no documentation of the system available, the installation contractor is no longer in business, and you are responsible for ensuring the system's operational safety. In this case, you might opt to adopt IIAR as your RAGAGEP because it is the most recognized best practice. Under these circumstances, the provisions of IIAR 9 represent the minimum standards you must meet. At this point in the flow chart, no further explanation is necessary. IIAR 9 is applicable because it was adopted due to a lack of knowledge about the best practices that were originally used.

Let's examine the next point that asks, "Is the original code/standard provision more restrictive than technical provisions in IIAR 9?" At this point, you need to identify which RAGAGEP was chosen for the system's initial design or any recent updates or expansions. For instance, consider an ammonia system installed in 2018 for a cold storage facility using the IIAR library as their RAGAGEP. More stringent requirements might be found in another IIAR library book, like the design book (book 2). Let's compare the provisions of IIAR 2 with those of IIAR 9, using the Ammonia Detection Alarm Response as an example:

IIAR 2 - 2021 - 6.13.2 Alarm Response:

6.13.2.2 *Detection of ammonia concentrations equal to or exceeding 25 ppm shall activate visual indicators, audible alarms, and provide a notice to a monitored location. The visual indicator and audible alarm shall be permitted to reset automatically if the ammonia concentration drops below 25 ppm.

6.13.2.3 *Detection of ammonia concentrations equal to or exceeding 150 ppm (1/2 IDLH) shall activate visual indicators and an audible alarm and shall activate emergency ventilation, where such is required in accordance with Section 6.14.7.

IIAR 9 - 2020/2024 - 7.3.12.2 Alarm Response: At a minimum, the machinery room alarm response shall be at an appropriate arrangement for the following to occur:

1. Activates an alarm to a monitored location so an immediate response can be set in place at a detected concentration of no higher than 50 ppm.

2. *Activate emergency ventilation at a detected concentration of no higher than 1000 ppm.

When comparing the provisions of IIAR 2 to those of IIAR 9 for alarm response, IIAR 2 is more stringent as it mandates an alarm at 25 ppm, whereas IIAR 9 requires an alarm at 50 ppm. Additionally, IIAR 2 necessitates emergency ventilation at 150 ppm, while IIAR 9 requires it at no higher than 1000 ppm. As illustrated by the examples provided, if IIAR 2 had been adopted during the 2018 ammonia system installation, IIAR 9 would not apply because the existing IIAR 2 codes and standards are more restrictive.

We hope that these straightforward explanations will assist you in the decision-making process if the IIAR 9 provisions pertain to your ammonia refrigeration system.

Stay tuned to the MySafety blogs. Reach out to us if you have additional questions or concerns. Our team will be pleased to assist you.

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IIAR 9 System Applicability